The effect of co-ingesting rice and liquid on glycemic response and gastric emptying in healthy subjects

Postprandial glycemic response is closely associated with gastric emptying rate. However, the effects of combining carbohydrates with liquid on gastric emptying and glycemic response are complicated. Here, we investigated the effect of co-ingesting rice and liquid in different ways on gastric emptying and glycemic response in healthy subjects. We performed a randomized crossover study in 12 healthy females. Three types of test meal were prepared: 150 g white rice (rice), 150 g white rice served alongside 200 mL of green tea (rice + tea), and 150 g white rice with 100 mL green tea poured over and served alongside 100 mL green tea (blend). After eating the test meal, measurements of postprandial glucose were performed, and breath samples for gastric emptying evaluation using (1-¹³C)-labeled sodium acetate breath test were collected for 120 min. Consumption of rice with liquid (both "rice + tea" and "blend") induced significantly higher postprandial glycemic responses, in addition to significantly higher gastric emptying rates, than eating rice only. There were significant positive correlations between gastric emptying rate and postprandial glucose response. Our findings demonstrated that compared with eating rice only, drinking liquid when eating rice causes an increase in postprandial blood glucose levels due to accelerated gastric emptying.